The aim of the proposed work is to investigate some pathogenetic mechanisms inducing nephritis in man and to study the pathogenesis, and possibly the prevention, of lesions developing in renal allografts. Serum samples and renal tissues obtained from patients with glomerulonephritis or with renal grafts will be studied in order to detect antibodies, complement, antigen-antibody complexes or cells inducing tissue injury. Comparable studies will be performed in animals with immunologically-mediated nephritis. Attempts will be made to identify the antigen(s) present in immune complexes which localized in the kidney as well as in extra-renal organs and to establish whether damage is induced by immune complexes formed "in situ" or in the circulation. The presence of anti-TBM antibody will be correlated with severity and histologic characteristics of tubulointerstitial lesions. The role of pressure perfusion in renal allograft will be studied by using techniques and devices which may minimize endothelial damage responsible for hyperacute rejection. BIBLIOGRAPHIC REFERENCES: Cerra, F.B., Raza, S.T., Andres, G.A., and Siegel, J.H. Structural analysis of pulsatile perfusion vs. cold storage renal preservation, Surgical Forum (in press), 1977. Andres, G.A., Hsu, K.C. and Seegal, B.C. Immunological techniques for the identification of antigens or antibodies by electron microscopy. In: "Handbook of Experimental Immunology", D.M. Weir, Ed., 3rd Edition, Blackwell Sci. Pub. Oxford, 1977, in press.